Closed loop gas cooling

ABSTRACT

An apparatus and a process for producing generated gas wherein the generated gas is cooled and then a portion recirculated into the generated gas as it leaves the generator. Such serves to rapidly cool the generated gas so as to inhibit or prevent formation of solid carbon particles and preventing change of chemical analysis.

United States Patent [191 Roberts et al.

[ June 11, 1974 CLOSED LOOP GAS COOLING [75] Inventors: Frederick W. Roberts, Southport;

Virgil D. Drummond, Fairfield, both of Conn.

[73] Assignee: Rolock Incorporated, Fairfield, Conn.

[22] Filed: Dec. 30, 1971 [21] Appl. No.: 213,890

[52] US. Cl 165/1, 165/108, 208/48 [51] Int. Cl F28f 13/06 [58] Field of Search 165/1, 108; 208/48 [56] References Cited UNITED STATES PATENTS 2,488,267 ll/l949 Cassie 165/108 Primary Examiner-Charles Sukalo Attorney, Agent, or Firm-Smythe & Moore [5 7] ABSTRACT An apparatus and a process for producing generated gas wherein the generated gas is cooled and then a portion recirculated into the generated gas as it leaves the generator. Such serves to rapidly cool the generated gas so as to inhibit or prevent formation of solid carbon particles and preventing change of chemical analysis.

2 Claims, 2 Drawing Figures Pmmmww 1914 3.615666 INVENTORS REFER/0r M ROBERTS ATTORNEYS CLOSED LOOP GAS COOLING Various gases useable for providing a desired atmosphere for treating metals, which can be termed generator or atmosphere gas, have been generated by passing suitable gases through a heated chamber in which is positioned a heated catalyst. When the cracked or generated gas emerges from the heating chamber, steps have been taken to cool the generated gas as rapidly as possible. A slow cooling of the generated gas will cause formation of solid carbon particles therein. Since the formation of carbon particles is undesirable, various arrangements have been proposed to cool the generated gas rapidly so as to prevent formation of such carbon. Previous known arrangements for the rapid cooling of a generated gas are not satisfactory since such cooling apparatus have been too complex and expensive, not effective in operation or have cooled at such a slow rate as to make use of such apparatus commercially unfeasible and have not prevented formation of solid carbon particles.

One of the objects of the present invention is to provide an improved apparatus and process to rapidly cool generated gas so as to prevent the formation of carbon after the gas has been generated.

According to one aspect of the present invention, a gas generator may have an outlet line for gas generated therein with a heat exchanger means positioned in the outlet line to cool the generator gas. A bypass line is connected from the outlet line downstream of the heat exchanger means to said outlet line upstream of the heat exchanger means to a point adjacent the outlet of the gas generator so as to define a closed loop.

A process according to the present invention may comprise cooling the gas generated in a gasgenerator and then recirculating a portion of the cooled gas into the generated gas so as to rapidly cool the generator gas and to prevent formation of carbon.

Other objects, advantages and features of the present invention will become apparent from the accompanying description and drawings, which are merely exemplary.

In the drawings:

FIG. 1 is a schematic diagram of the gas generating and cooling apparatus according to the present invention; and

FIG. 2 is a longitudinal sectional view of one type of connection of the bypass line to the outlet of the gas generator.

Proceeding next to the drawings wherein like reference symbols indicate the same parts throughout the various views, a specific embodiment of the present invention will be described in detail.

As may be seen in FIG. 1, the apparatus comprises a conventional gas generator for generating gas by passing a gas to be cracked through a heated catalyst or other means for dissociation. Such gas generators are well known in the art for producing atmosphere gas.

The generator has an outlet 11 through which the generated gas flows to outlet line 12 leading to a suitable cooling or heat exchanger 13. The heat exchanger may have a coil 14 therein for receiving the generated gas or the generated gas may be fed through a coil (not shown) and the cooling medium circulated therearound. On the other downstream side of the heat exchanger 13, there is connected a bypass line 15 having a pump 16 therein, the bypass line being connected back to the outlet of the gas generator at 17.

One type of connection is seen in FIG. 2 which comprises a substantially cylindrical chamber 18 sealingly mounted on outlet line 11. A suitable flexible connection (not shown) may be made between the chamber 18 and pipe 11. That portion of the outlet 11 enclosed within the chamber 18 is provided with a plurality of openings 19 through which the cooled recirculated gas can mingle with the hot generated gas from 10. The bypass line is connected at 17 to the chamber 18 from which the recirculated gas is drawn through the openings 19 to be intermixed with the hot generated gas.

Merely as one example, the temperature of the generated gas passing from generator l0 is in the range of l,850 F. The generated gas, after being mixed with the recirculated gas at about 200 F., is in the range of 800 R, such reduction from l,850 F. being sufficiently rapid so that solid carbon particles will not form. For example, A.G.A. class 300 endothermic gas should be cooled from aproximately l,200 F. to 900 F. as rapidly as possible. Thus, the rapid cooling must take place during the critical range. Thereafter, the gas can be cooled as desired. Other gases may exhibit different critical ranges as is known in the art. As an example of operation, the generated gas through pipe 11 can be 1,500 CFH, the volume in pipe 12, 4,500 CFH, the volume in pipe 15, 3,000 CFH and the output volume in pipe 20, 1,500 CFH. CFH is at standard temperature and pressure as used in the art.

The temperature of the mixed bypass gas and generated gas can be about 200 F. after passing through heat exchanger 13.

The rapid intermingling of cool gas with the hot gas is essential for prevention of carbon particle formation and changeof gas composition. Such intermingling of the gas is effective as compared with merely bringing the hot gas into contact with a cooled surface.

Thus, the apparatus according to the present invention may be used to carry out a process wherein the gas generated in a gas generator is cooled and then a portion of this cooled gas is recirculated into the generated gas. The result is a rapid and effective cooling of the generated gas so as to prevent formation of carbon therein.

It will be understood that various details of construction and arrangement of parts may be made without departing from the spirit of the invention except as defined in the appended claims.

What is claimed is:

l. A process for producing atmosphere gas comprising the steps of producing in a catalytic furnace hot generated atmosphere gas, discharging the heated generated gas after the gas has been generated, indirectly cooling the generated gas, and rapidly cooling the generated gas by recirculating a portion of the cooled generated gas directly into the generated gas after it has been produced and before it has been cooled so as to rapidly cool the same to inhibit formation of solid carbon particles.

2. An atmosphere generating system as claimed in claim 1 including a pump in said bypass line. 

1. A process for producing atmosphere gas comprising the steps of producing in a catalytic furnace hot generated atmosphere gas, discharging the heated generated gas after the gas has been generated, indirectly cooling the generated gas, and rapidly cooling the generated gas by recirculating a portion of the cooled generated gas directly into the generated gas after it has been produced and before it has been cooled so as to rapidly cool the same to inhibit formation of solid carbon particles.
 2. An atmosphere generating system as claimed in claim 1 including a pump in said bypass line. 